For example, a notebook personal computer (hereinafter abbreviated as “notebook PC”) has an operational unit having a keyboard on the top face thereof and a display unit having a display screen. In a general structure, the display unit is rotated, on a rearward side of the operational unit serving as a rotation axis, between a closed state in which the display unit is laid on the operational unit and an open state in which the display unit is opened with respect to the operational unit through lifting of a front end of the display unit in the closed state. In this case, the display unit has such a structure that the display unit is opened and closed with friction so that the display unit is stopped at any angle in the open state. Further, to prevent unintentional opening of the display unit in the closed state, for example, the display unit is provided with a hook and the operational unit is provided with a locking hole into which the hook is inserted and locked. In order to open the display unit in the closed state, for example, a protruding operation button is provided at a front-end face of the display unit in the closed state and the operation button is pushed in the front-end face of the display unit thereby releasing the hook so that the display unit is opened. However, merely releasing the hook at the push of the operation button is not enough to open the display unit because opening and closing of the display unit is accompanied by friction and therefore, operation for lifting the front end of the display unit is desired. It is preferable to realize easy opening operation with one hand after release of the hook.
Although the notebook PC is described as an example here, the above-mentioned circumstances are not limited to the notebook PC and are common to any electronic device having a first unit and a second unit opened and closed with respect to the first unit, such as tablet PCs of convertible type.
For example, see Japanese Patent Laid-open Publication No. H11-312876.